Agents assigned to the Interstate 35 immigration checkpoint between Laredo, Texas, and San Antonio observed a refrigerated tractor-trailer rig approaching the primary inspection lane last week. During an initial interview, the driver consented to a search of his vehicle, according to information obtained from Laredo Sector Border Patrol officials.

The driver moved the rig to a secondary inspection station where agents conducted a search for contraband or smuggled humans. The agents discovered 76 illegal immigrants locked in the cold trailer. The agents carried out a medical screening and found all of the migrants to be in good condition.

An immigration interview identified 62 of the migrants to be Mexican nationals. The others came from Guatemala (11), Honduras (2), and El Salvador (1).

Agents apprehended all 76 and transported them to the station for processing. They also arrested the driver and seized the tractor-trailer.

Homeland Security Investigation special agents from U.S. Immigration and Customs Enforcement assisted in the investigation, officials stated.

In February, Laredo Sector Border Patrol agents apprehended 3,118 migrants who illegally crossed the border from Mexico. Only 311 of those were family units and unaccompanied minors, according to the February Southwest Border Migration report released last week by U.S. Customs and Border Protection. One year ago, agents in this sector apprehended 2,671 migrants — an increase this year of 16 percent.

These numbers stand in sharp contrast to other sectors like El Paso where agents reported a 1,689 percent increase in the apprehension of family unit migrants.

The El Paso and Rio Grande Valley Sectors combined apprehended 24,957 migrant family units in just 28 days. This amounts to an average of 891 migrants per day in these two sectors of the U.S.-Mexico Border.

Bob Price serves as associate editor and senior political news contributor for the Breitbart Border team. He is an original member of the Breitbart Texas team. Follow him on Twitter @BobPriceBBTX and Facebook.